The GAPO syndrome is an extremely rare autosomal recessive disease that presents as main characteristics evident growth retardation, alopecia, pseudoanodontia, progressive optic atrophy and a typical face. Until now, only 30 patients have been reported in the medical literature (nine of them from Brazil, including the three cases described in the present article). This study describes three siblings with GAPO syndrome, two female and one male, the children of consanguineous parents (first-degree cousins, inbreeding F = 1/16), who are older than the previously described patients, presenting the characteristic phenotype besides serious bone alterations in the lower limbs, which had not yet been observed.